Nintendo's rumored mobile initiative could begin as early as this year, according to a report from Japanese newspaper Nikkei. But don't expect to see Mario, Zelda, or any of Nintendo's other franchises in mobile form (at least not outside of the 3DS).
According to a translation by analyst Dr. Serkan Toto, the paper reports that Nintendo will instead look at mobile devices for a way to market its console games. In addition to offering videos and information about its new games to mobile users, Nintendo is also looking at offering playable "mini games" based on its titles. Think of it as a demo, but intended to familiarize the player with the game and hopefully convince them to purchase the full-fledged console edition, available only on Nintendo hardware like the Wii U or 3DS.
At this point, it doesn't appear as though Nintendo is planning to offer paid or freemium games on smartphones, but I think playable demos or "mini games" is certainly a good start. Just about every "kid" has a mobile device these days, but not everyone has Nintendo hardware; a playable demo could introduce a kid to a new Nintendo franchise that they otherwise might not have ever heard of.
More details are expected to come during a briefing for investors this Thursday.